In the field of remote control of a motor vehicle, a remote-control device enables execution of a basic function such as remote locking/unlocking of the motor vehicle with a range of the order of approximately 50 meters. However, more sophisticated functions are now executed via said remote-control device, such as comfort functions (remote pre-warming of the vehicle) or functions that display the status of the vehicle on a screen of the remote-control device. These functions necessitate long-range communication. To this end, the electronic assembly for the remote-control device includes a transmitter/receiver and a frequency amplifier that enable communication to be established between said remote-control device and the motor vehicle and thus a range of the order of 500 meters to be obtained. Moreover, the electronic assembly includes an electric power source (button cell) to power all of these electronic components. The button cell delivers a voltage of the order of 3 V. The advantage of a button cell is that it is of small overall size compared to a stick cell, which is of interest for the remote-control device, in which space is limited.
However, a disadvantage of this prior art resides in the fact that the frequency amplifier draws a high current, of the order of 100 mA, when it is communicating with the motor vehicle and notably on each radio-frequency transmission. The button cell, which has an internal resistance, suffers a voltage drop that is very large, of the order of 1 V, when the high current necessary for the frequency amplifier flows. Consequently, the button cell is discharged very rapidly and therefore supplies only 2 V. This excessively rapid discharge and this high voltage drop therefore lead to malfunctions of the remote-control device including said electronic assembly such as a falling below an operating voltage and consequently a reduction of the communication range of said remote-control device or even its reinitialization with loss of information. It will be noted that the limit operating voltage of such a remote-control device is around 2 V.
In this context, the present invention aims to resolve the disadvantage referred to above.